Folding of flexible sheet materials

ABSTRACT

The present invention provides apparatus for forming a fold in a length of flexible sheet material comprising a horizontal support for supporting a length of flexible sheet with a portion thereof to be folded lying over a transverse edge of the support, a horizontal cord arranged above and beyond said edge of the support, means for downwardly deforming the cord so that at least a portion thereof lies below the level of said support beneath said portion of the sheet to be folded when a sheet is present on the support, and means for tensioning the cord against the action of said deforming means to straighten the cord and to thereby raise said portion of the sheet, forming a fold therein around the cord. The apparatus is intended to be used primarily in a hemming machine having a machine head, for forming a seam in a fold made in the sheet, displaceably mounted for movement in a direction parallel to said transverse edge of the support, such that the head traverses longitudinally along a fold formed by the cord.

United States Patent Fryatt [54] FOLDING OF FLEXIBLE SHEET MATERIALS [72] Inventor: Leslie Alva Fryatt, 24 Highergate Road,

l-luncoat, Accrington, Lancashire, En-

gland [73] Assignee: J. L. Fenner 8: Co. Limited, Marfleet, Hull, Yorkshire, England [221 Filed: June 19,1970

[21] Appl. No.: 47,799

[30] Foreign Application Priority Data June 27, 1969 Great Britain ..32,495/69 [52] US. Cl ..1l2/l2l.14, 112/147, 270/93, 156/227, 156/513 [51] Int. Cl ..D05b 3/00, D05b 35/02 [58] FieldotSearch .1l2/2,12l.l4,121.11,]47, 112/141, 121.29; 156/513, 227, 443; 270/61, 66, 86, 93

[56] References Cited UNITED STATES PATENTS 2,518,147 8/1950 Johnson etal. ..112/l21.14 2,740,457 4/1956 Wood, Jr. et a1 ..112/141 X Feb. 1, 1972 Primary Examiner.lames R. Boler Attorney-Scrivener, Parker, Scrivener & Clarke [5 7] ABSTRACT The present invention provides apparatus for forming a fold in a length of flexible sheet material comprising a horizontal support for supporting a length of flexible sheet with a portion thereof to be folded lying over a transverse edge of the support, a horizontal cord arranged above and beyond said edge of the support, means for downwardly defonning the cord so that at least a portion thereof lies below the level of said support beneath said portion of the sheet to be folded when a sheet is present on the support, and means for tensioning the cord against the action of said deforming means to straighten the cord and to thereby raise said portion of the sheet, forming a fold therein around the cord. The apparatus is intended to be used primarily in a hemming machine having a machine head, for forming a seam in a fold made in the sheet, displaceably mounted for movement in a direction parallel to said transverse edge of the support, such that the head traverses longitudinally along a fold formed by the cord.

14 Claims, 6 Drawing Figures PATENTED FEB 1 i972 SHEET 1 BF 5 PATENTEU FEB 1 i972 SHEET 2 BF 5 PATENTEU FEB H972 Sum 3 of 5 3,638,592

PATENTED FEB 1 1972 saw a nr 5 FOLDING OF FLEXIBLE SHEET MATERIALS The present invention relates to the folding of flexible sheet materials, such as cloth or plastics sheet, and particularly to folding apparatus for use in an automatic hemming machine.

Presently employed methods of folding flexible sheet materials include the use of air blasts and knife edges neither of which is particularly suitable for use with the automatic hemming machine.

According to the present invention, apparatus for forming a fold in a length of flexible sheet material comprises a horizontal support for supporting a length of flexible sheet with a portion thereof to be folded lying over a transverse edge of the support, a horizontal cord arranged above and beyond said edge of the support, means for downwardly deforming the cord so that at least a portion thereof lies below the level of said support beneath said portion of the sheet to be folded when a sheet is present on the support, and means for tensioning the cord against the action of said deforming means to straighten the cord and to thereby raise said portion of the sheet, forming a fold therein around the cord.

When the apparatus is to be used in a hemming machine, a

machine head for forming a seam in a fold made in the sheet is displaceably mounted for movement in a direction parallel to said transverse edge of the support, each that the head traverses longitudinally along a fold formed by the cord.

When the sheet material to be hemmed is cloth, the machine head is in the form of a sewing mechanism and when the sheet is of plastics material, the machine head is a welding device.

The invention will be further described, by way of example, with reference to the accompanying drawings: in which:

FIG. 1 is a diagrammatic side elevation illustrating the operating principle of folding apparatus in accordance with the present invention;

FIG. 2 is a side elevation of part of a hemming machining embodying folding apparatus in accordance with the present invention;

FIG. 3 is a plan view of the part of the hemming machine shown in FIG. 2;

FIG. 4 is a side elevation of a further part of the hemming machine of FIG. 2;

FIG. 5 is a partial sectional view on the line V-V of FIG. 2 showing material being folded into a hem; and

FIG. 6 is a partial sectional view on the line VI-VI of FIG. 2 when the rotatable fork has been displaced through 90 anticlockwise from its position in FIG. 2.

FIG. 1 illustrates a basic folding apparatus in accordance with the invention which, in this case, is adapted to cooperate with a machine 10 which performs an operation, such as hemming or seaming, upon material folded by the apparatus. The apparatus includes a flexible cord or cable 12, preferably of stranded metal, which is attached to a fixed point 14 at its one end and to the periphery of a rotatable pulley 16 at its other end. From the fixed point 14, the cord 12 first passes around the grooved periphery of a pulley wheel 18 which is rotatably mounted on a frame 17 bearing the machine 10. The upper horizontal tangent to the periphery of the pulley wheel 18 is arranged to intersect the fixed point 14 whereby the cord I2 is horizontal when it is pulled taught between the pulley I8 and the fixed point 14. The portion 12a of the cord 12 extending between the fixed point 14 and the pulley I8 is arranged above a vertical channel in a horizontal bench 20, means being provided at either end of the cord portion 12a for selectably holding this portion 12a in said channel below the surface of the bench 20. The means for selectably holding the cord 12a in this manner comprises a pivotable forked lever 22 adjacent the fixed point 14 and a pivotable forked lever 24 which is attached to the frame 17 adjacent the pulley 18. The levers 22, 24 are biassed, for example by springs (not shown), so that the cord portion 12a normally lies below he level of the bench 20. With the cord in this state, a length of material to be folded is laid on the bench with its portion to be folded lying over the channel. When the cord 12 is pulled taught, it

deflects the levers 22, 24 in the anticlockwise and clockwise directions respectively and rises to its upper portion shown by a dotted line FIG. I where it extends horizontally between the fixed point 14 and the periphery of the pulley 18. In rising to this position, the cord 12 raises the material to form a double thickness of material suitable for forming a hem. The fold is improved by the provision of a horizontal bridge located just above the material and over the edge of the channel around which the material passes when it is raised by the cord whereby the material extends substantially vertically upwards from the bench to the fold formed by the cord.

After passing around the pulley I8, the cord extends horizontally to a fixed pulley 26, vertically downwards to a fixed pulley 28 and horizontally to the pulley I6. A further cord 30 is attached at its one end to the frame 17 and at its other end to the periphery of a pulley 32 rigidly attached to the pulley l6 and of half the diameter of pulley I6. Intermediate its length, the wire 30 passes around fixed pulleys 34, 36. Pulley 16 is further provided with a toothgear wheel 38 which engages with a rack 39 adapted to be linearly displaced by means of a hydraulic piston and cylinder unit 40.

When the pulleys l6 and 32 are rotated by the rack 39, the frame 17 is drawn to the left, as seen in FIG. I, on a rail, tension being maintained in the cords I2 and 30 by virtue of the ratio of the peripheral diameters of these pulleys. The frame 17 and consequently the machine 10 are moved from engagement with a fixed stop 44 to the left, the pulley 18 being ar' ranged to run inside the fold in the material whereby the fold enters the machine 10 where it is sewn or welded depending on the material in question. The machine is drawn across until the entire length of the fold has been transversed and hemmed, the material falling back to the bench as it is hemmed. When the hemming operation is complete, the machine 10 is drawn back to its starting position in engagement with the stop 44 by reversing the rotation of the pulleys 16, 32. The apparatus is then ready to perform its next hemming operation.

FIGS. 2 to 6 illustrate a practical hemming machine which embodies the invention and which operates in the manner of the apparatus of FIG. I. In order to aid the understanding of the operation of the machine of FIGS, 2 to 6, those parts which correspond to parts in FIG. I have been given the same reference numerals.

Thus, in FIGS. 2 and 3, the reference numeral I0 denotes a sewing machine which is mounted on a frame 17 with its needle 50 arranged to reciprocate in a horizontal plane. The frame 17 is slidable on a horizontal rail 52 by means of wheels 54, only one of which is shown in FIG. 2. The frame I7 has a depending leg 56 carrying a further wheel or wheels (not shown) which engage a further rail (not shown) to provide support for the machine I0.

A pulley I8 is rotatably mounted on a boss 55 of the frame 17, the pulley I8 having a groove extending around its periphery which receives a cord 12. Independently, rotatably mounted on the boss 55 is a bar 58 to which is connected a flat plate 60. The plate 60 is generally rectangular and lies in the same plane as the pulley 18, the plate 60 being shaped at its edge adjacent to the pulley 18 to conform to the circular shape of the pulley 18. The purpose of the plate 60, as will become apparent below, is to move into the fold formed in a sheet of material 61 in advance of the pulley I8 to act as a guide therefor.

Extending from the bar 58 in generally the opposite direction to the plate 60 is a bar 62 having an eye ring 64 at its outer end which receives the cord I2. The eye ring 64 could alternatively be replaced by a pulley wheel (not shown). Also attached to the bar 58 is an elongate member 66 which extends upwardly beyond the top of the pulley 18 before bending back on itself and terminating in a fork 68. The fork 68 engages the cord I2 as seen in FIG. 2, the bar 58 and the member 66 being rotatable anticlockwise through as seen in FIG. 2 from a first position (FIG. 2) in which the cord 12 is held below the level of a bench 20 to a second position (FIG.

6) in which the plate 60 is in front of the pulley 18, in a direction away from the machine 10, and the member 66 is clear of the cord 12 which is then able to extend horizontally from the periphery of the pulley 18.

The frame 17 and machine I are shown in FIG. 2 when located at one side of the apparatus adjacent one end of the bench 20. At the other end of the apparatus, adjacent the other end of the bench 20, one end of the cord 12 is attached to a fixed point 14. The cord 12 passes around a pin 70 attached to one end of a bellcrank lever 72 whose other end is pivotably mounted on a fixed part of the apparatus whereby the lever 72 is pivotable in the plane of the pulley 18. The lever 72 is pivotable between two positions corresponding to the two positions of the bar 58 whereby in one position (FIG. 4) the cord I2 is guided below the level of the bench 20 and in the other position the cord is not engaged so that it can extend horizontally from the fixed point 14 towards the pulley 18. The lever 72 is biassed into said second position by a spring or springs 74 but normally held in said first position by means of a cable 76.

Mounted just above the bench to allow the material to pass therebetween is a bridge 78 which ensures that when the cord is raised to form a fold, the material extends vertically upwards to he cord from the bench, as seen in FIGS. 5 and 6. Extending horizontally across the apparatus are a pair of strips 80 between which the cord 12 is arranged to lie when in said second position so that the material is guided by the strips to achieve a tight fold around the cord 12. Located transversely of the pulley I8 is a guide plate 82 for guiding the material in its passage through the machine 10.

The components of the apparatus so far described form a single fold in the material which in the present machine is to serve as a hem. However, if just the single fold is sewn together, the rough edge of the sheet of material would be left exposed which would be liable to fray in use. Thus, it is desirable to fold under the outer margin of the first fold to form a double fold thereby concealing the rough edge and producing a neat appearance. In order to accomplish this second, marginal fold, a subsidiary folding device indicated generally by the reference numeral 82 is provided which is located immediately behind the pulley 18, considered in the direction of movement of the machine along the folded material 61.

The folding device 82 comprises a pair of guide strips 84, 86 (see FIG. 2), the strip 84 being straight and the strip 86 being bent along the line 88 whereby it has a portion 86a on one side of the strip 84 and a portion 861) on the other side of strip 84. The depending free side 90 of the main fold of the material 61 is arranged to enter the gap between the strip 84 and the portion 86a of the strip 86 as the folding device 82 is moved to the right as viewed in FIG. 2. The strip portion 86b is so shaped that when the depending material portion 90 reaches the region of the bend 88 it is forced to bend inwardly on itself in an upward direction about the lower edge of the strip 84, (see FIG. 5) forming a double fold in the material. During its passage through the subsidiary folding device 82, the main fold in the material is clamped between the strips 80 by means of a pair of opposed pinch rollers 92 and by means of a clamping roller 94 and guide plate 96. The sewing needle 50 is located immediately rearwardly of the subsidiary folding device 82 whereby the double fold can be sewn to finalize the hem.

The apparatus described above with reference to FIGS. 2 to 6 is provided with a similar cord drive arrangement to the apparatus of FIG. I which is adapted to operate in a similar manner. An operating cycle of the machine is as follows.

A sheet of material is layed on the bench 20 beneath the bridge 78 with its edge to be hemmed lying over the cord I2 in the channel, the bar 58 being in its first position so that the cord 12 lies below the level of the bench 20. The hydraulic unit 40 is then actuated to pull the cord I2 in the direction of arrow A (FIG. 2). The first result of this is that the bar 58 is rotated anticlockwise by virtue of the action of the cord on the eye ring 64 so that the forked member 66 gradually allows the cord to rise. At the same time, the cable 76 is relaxed to enable the springs 7'4 to rotate the lever 72 clockwise and allow ing the other end of the cord to rise. The cord I2 rises until it extends horizontally between the pulley I8 and the fixed stop 14 lifting the material 61 with it so that the edge portion of the material hangs down from the cord (FIG. 6). Further pulling on the cable in the direction of arrow A causes the frame to be drawn to the right as seen in FIG. 2 so that the plate 60 and then the pulley 18 enter the fold, the plate 60 serving to hold the sides of the fold apart to allow the pulley I8 to enter. The free side 90 of the fold, which is on the far side of the pulley 18 as viewed in FIG. 2, then enters the subsidiary folding device as previously described and is folded under to achieve the double fold before entering the sewing head to be machined by the needle 50. The material released by the machine when the sewing operation has been completed so that it falls back onto the bench. When the machine has traversed the whole of the material, the sewing action is inhibited and the hydraulic unit is reversed to draw the frame I7 and machine 10 back to their starting positions by means of the cord 30. On return to the starting position, the tension is relaxed in the cord 12 so that the bar 58 returns to its first position under gravity, the cable 76 is tensioned, and the cord 12 returns to its starting position beneath the level of the bench 20.

Advantageously, two such sets of apparatus as described above are arranged facing one another with the sewing machines opposed, one set of apparatus being arranged for left-hand operation and the other for right-hand operation so that the opposed machines moved in the same direction across the bench. A cutter is provided between the two sets of apparatus whereby when a sheet of material is layed across the bench with the desired length of a finished sheet thereof projecting from on side of the bench, the cutter can be operated to sever the material to form the longitudinal edges of two sheets of material. When the two sets of apparatus are subsequently actuated, a hem is applied to said two edges simultaneously by the two machines respectively. The material is normally mounted on a roller or as a folded pile at the edge of the bench and is disposed that it can be pulled across the bench by an operator who stands at the opposite side to the material.

Although the machine 10 has been described as having a sewing needle 50 it could equally well be provided with a welding head for use in hemming plastics materials.

In order to maintain the tension in the cord 30 when the pulley 16 is initially rotated to move the cord portion I20 from its lower position to its upper position, a spring-biased tensioning pulley is provided which is carried on an arm (not shown) pivotably mounted on the same axis as the pulley 36. This ten sioning pulley is arranged to ensure that the machine I0 is retained in contact with the fixed stop 44 until the cord portion 12a has been fully raised to its upper horizontal position, the machine being thereafter allowed to move to the left, as seen in FIG. I, with the cord 30 tensioned by the tensioning pulley.

Iclaim:

1. Apparatus for forming a fold in a length of flexible sheet material comprising a horizontal support for supporting a length of flexible sheet material with a portion thereof to be folded lying over a transverse edge of said support; a horizontal cord located above and beyond said edge of the support; means for downwardly deforming the cord so that at least a portion thereof lies below the level of said support beneath said portion of the sheet to be folded when a sheet is present on said support; and means for tensioning the cord against the action of said deforming means to straighten the cord and to thereby raise said portion of the sheet to form a fold therein around said cord.

2. A hemming machine including folding apparatus according to claim I in which a machine head for forming a seam in a fold made in the sheet is displaceably mounted for movement in a direction parallel to said transverse edge of the support such that the head traverses longitudinally along a fold formed by the cord.

3. A hemming machine according to claim 2 in which the machine head is a sewing mechanism for seaming the fold when the sheet material is cloth.

4. A hemming machine according to claim 2 in which the machine head is a welding device for seaming the fold when the sheet is of plastics material.

5. A hemming machine according to claim 2 wherein one end of the cord is connected to a fixed member and the other end is connected to a winch, the machine further including a pulley located intermediate the ends of the cord and around which the cord passes, the pulley being arranged with the upper horizontal tangent to its periphery at the same level as said fixed member whereby the cord is horizontal when tensioned between said fixed member and said pulley.

6. A hemming machine according to claim 5 wherein said pulley is connected to the machine head for movement therewith whereby when the winch is actuated to tension the cord, said portion of the cord first rises from its initial position below the level of said support to its horizontal position between said fixed member and the pulley to thereby straighten the cord, whereupon further actuation of the winch causes the pulley and the machine head attached thereto to be displaced in a direction towards said fixed end of the cord.

7. A hemming machine according to claim 6 further including means for guiding a fold formed and supported by the cord over the pulley and into the path of the machine head whereby the fold is continuously machined when the machine head traverses the edge of said support.

8. A hemming machine according to claim 7 wherein said deforming means comprises a pair of forked arms, one of which is located adjacent the fixed end of the cord and the other of which is located adjacent the pulley, the forked arms being angularly displaceable between a first position, in which they engage and deform the cord to form said portion extending below said support, and a second position in which the cord is allowed to extend horizontally between said fixed member and the periphery of the pulley.

9. A hemmingmachine according to claim 8 wherein said other one of the forked arms is pivotably mounted for independent rotation about the same axis as the pulley, the machine including means for automatically moving said other of the arms from its first to the second position when the cord is tensioned by actuation of the winch, said one of the forked arms being spring biassed from its first to its second position but being normally maintained in its first position by releasable holding means.

10. A hemming machine according to claim 9 further in cluding an additional folding device which is located between the pulley and the machine head and which is arranged to receive the depending free side of a fold formed around the cord when the fold is traversed by the machine head and to bend under free edge of this side of the fold to form a double fold which passes to the machine head.

11. A hemming machine according to claim 10 wherein the additional folding device comprises first and second guide strips the first of which is straight and the second of which is bent and is so shaped that when the depending free side of the main fold formed by the cord passes between the strips it is bent inwardly on itself by the second strip in an upward direction about a lower edge of the first strip to form said double fold in the material.

12. A hemming machine according to claim 11 further including a pair of elongate, fixed guides located above and along the whole length of the edge of the support so as to lie parallel to and on either side of the cord when the cord is in its upper horizontal position between said fixed member and the pulley periphery whereby the apex of a fold formed by the cord is gripped between said guides to support the fold.

13. Apparatus according to claim 12 further including a horizontal bridge located above the support so as to be parallel to and adjacent said ed e of the support, the bridge bein spaced sufficiently above t e support to allow the passage 0 the sheet of material therebetween thereby providing a corner around which the material is bent when the cord is raised to form a fold in the material.

14. Two sets of apparatus according to claim 2 when mounted with the edges of their respective supports adjacent and parallel to one another, one set of apparatus being arranged for operation to the right and the other for operation to the left whereby the two machine heads are displaceable simultaneously in the same direction to seam the respective edges of two lengths of material formed by cutting a single length of material laid across said two supports by means of a cutter disposed between the two sets ofapparatus.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3.638.592 Dated 'Fnhrna'm 1 1 en) Inventor(s) Leslie Alva Fryatt It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

On the cover sheet, Q [73] "J; L. Fenner & Co. Limited," should read J. H. Fenner &'Co. Limited,

Signed and sealed this 26th day of December 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK I Attesting Officer Commissioner of Patents ORM FWD-1050 (IO-69) uscoMM-oc scan-poo W U.S. GOVERNMENT PRINTING OFFICE I969 0-868-384, 

1. Apparatus for forming a fold in a length of flexible sheet material comprising a horizontal support for supporting a length of flexible sheet material with a portion thereof to be folded lying over a transverse edge of said support; a horizontal cord located above and beyond said edge of the support; means for downwardly deforming the cord so that at least a portion thereof lies below the level of said support beneath said portion of the sheet to be folded when a sheet is present on said support; and means for tensioning the cord against the action of said deforming means to straighten the cord and to thereby raise said portion of the sheet to form a fold therein around said cord.
 2. A hemming machine including folding apparatus according to claim 1 in which a machine head for forming a seam in a fold made in the sheet is displaceably mounted for movement in a direction parallel to said transverse edge of the support such that the head traverses longitudinally along a fold formed by the cord.
 3. A hemming machine according to claim 2 in which the machine head is a sewing mechanism for seaming the fold when the sheet material is cloth.
 4. A hemming machine according to claim 2 in which the machine head is a welding device for seaming the fold when the sheet is of plastics material.
 5. A hemming machine according to claim 2 wherein one end of the cord is connected to a fixed member and the other end is connected to a winch, the machine further including a pulley located intermediate the ends of the cord and around which the cord passes, the pulley being arranged with the upper horizontal tangent to its periphery at the same level as said fixed member whereby the cord is horizontal when tensioned between said fixed member and said pulley.
 6. A hemming machine according to claim 5 wherein said pulley is connected to the machine head for movement therewith whereby when the winch is actuated to tension the cord, said portion of the cord first rises from its initial position below the level of said support to its horizontal position between said fixed member and the pulley to thereby straighten the cord, whereupon further actuation of the winch causes the pulLey and the machine head attached thereto to be displaced in a direction towards said fixed end of the cord.
 7. A hemming machine according to claim 6 further including means for guiding a fold formed and supported by the cord over the pulley and into the path of the machine head whereby the fold is continuously machined when the machine head traverses the edge of said support.
 8. A hemming machine according to claim 7 wherein said deforming means comprises a pair of forked arms, one of which is located adjacent the fixed end of the cord and the other of which is located adjacent the pulley, the forked arms being angularly displaceable between a first position, in which they engage and deform the cord to form said portion extending below said support, and a second position in which the cord is allowed to extend horizontally between said fixed member and the periphery of the pulley.
 9. A hemming machine according to claim 8 wherein said other one of the forked arms is pivotably mounted for independent rotation about the same axis as the pulley, the machine including means for automatically moving said other of the arms from its first to the second position when the cord is tensioned by actuation of the winch, said one of the forked arms being spring biassed from its first to its second position but being normally maintained in its first position by releasable holding means.
 10. A hemming machine according to claim 9 further including an additional folding device which is located between the pulley and the machine head and which is arranged to receive the depending free side of a fold formed around the cord when the fold is traversed by the machine head and to bend under free edge of this side of the fold to form a double fold which passes to the machine head.
 11. A hemming machine according to claim 10 wherein the additional folding device comprises first and second guide strips the first of which is straight and the second of which is bent and is so shaped that when the depending free side of the main fold formed by the cord passes between the strips it is bent inwardly on itself by the second strip in an upward direction about a lower edge of the first strip to form said double fold in the material.
 12. A hemming machine according to claim 11 further including a pair of elongate, fixed guides located above and along the whole length of the edge of the support so as to lie parallel to and on either side of the cord when the cord is in its upper horizontal position between said fixed member and the pulley periphery whereby the apex of a fold formed by the cord is gripped between said guides to support the fold.
 13. Apparatus according to claim 12 further including a horizontal bridge located above the support so as to be parallel to and adjacent said edge of the support, the bridge being spaced sufficiently above the support to allow the passage of the sheet of material therebetween thereby providing a corner around which the material is bent when the cord is raised to form a fold in the material.
 14. Two sets of apparatus according to claim 2 when mounted with the edges of their respective supports adjacent and parallel to one another, one set of apparatus being arranged for operation to the right and the other for operation to the left whereby the two machine heads are displaceable simultaneously in the same direction to seam the respective edges of two lengths of material formed by cutting a single length of material laid across said two supports by means of a cutter disposed between the two sets of apparatus. 